Incidence and risk factors of atrial fibrillation in a surgical intensive care unit

Objective

To evaluate the incidence and risk factors of atrial fibrillation (AF).

Design

A prospective, observational study.

Setting

A 21-bed teaching surgical intensive care (SICU).

Patients

All patients with new onset of AF admitted in the SICU between April and October 2001.

Interventions

None.

Measurement and results

A total of 453 patients were included. AF occured in 24 patients (5.3%). In univariate analysis advanced age, pre-existing cardiovascular disease, previous treatment by calcium-channel blockers, and Simplified Acute Physiologic Score (SAPS II) were significant predictors of AF. Patients with AF received significantly more fluids and catecholamines, and experienced more sepsis, shock (especially septic shock), and acute renal failure. The severity (SAPS II), the ICU workload (OMEGA), the ICU and hospital length of stay, and mortality were significantly increased in patients who developed AF. Multivariate analysis identified five independent predictors of AF: advanced age, blunt thoracic trauma, shock, pulmonary artery catheter, and previous treatment by calcium-channel blockers.

Conclusions

The incidence of AF in a SICU appeared more frequent than in the general population but less than in the cardiac surgery unit. The onset of AF reflects the severity of the disease and is associated with an increased mortality and morbidity. Five independent risk factors of AF were identified. AF seems to be more frequent after blunt thoracic trauma.

Table 1